Automobiles are generally provided with a number of locks to secure the automobile doors and trunk. These locks are generally disposed within apertures formed in the sheet metal of the automobile and retained therein to lie substantially flush with the exterior surface. It has been found, however, that these locks, and especially the trunk lock, are not effective against attempts at surreptitious entry by means of punching a hole in the automobile surface adjacent the locks and releasing the holding latch from within the hole.
As one means to inhibit these attempts to circumvent the lock mechanism, there is presently available a lock guard plate which consists of a flat steel plate, with an aperture formed therethrough, which is placed over the lock cylinder such that the key slot is exposed through the aperture, and permanently attached to the automobile surface by means such as one way screws. One such plate is Wolo Manufacturing Company item TC-5 trunk guard, which is attached externally to the surface of the trunk lid and reinforces the sheet metal in the vicinity of the lock cylinder.
While the use of such a device does inhibit unauthorized entry by means of punching a hole near the lock and releasing the holding latch, it has been found that entry may still be gained by removing the entire lock cylinder, either by retracting the lock through the plate aperture or by punching the lock mechanism into the car. The former may be accomplished either externally as by inserting a dent-puller into the key slot, or from behind through a hole punched into the automobile surface adjacent the lock plate. Punching-in of the lock is also easily accomplished since the lock is exposed through the aperture.